Multi-component implant assembly with dual articulating and/or rotating surfaces

ABSTRACT

An implant assembly for re-establishing a glenohumeral joint between a scapula and humerus. A first receiver is adapted to being mounted to a reconditioned glenoid cavity defined in the scapula, with a second receiver adapted to being mounted to a reconditioned humeral head associated with the humerus. A three dimensional and at least partially spherical shaped element is interposed between the first and second receivers for establishing at least one of articulating and rotating support at respective and spaced apart seating profiles.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of U.S. Ser. No. 61/526,404 and U.S. Ser. No. 61/526,388, both filed Aug. 23, 2011.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to a shoulder implant assembly and, more specifically, to a multi-component implant assembly incorporating a pair of modified and inwardly recessed receivers mounted to first and second shoulder joint defining bones. An intermediated positioned and spherical (or substantially spherical with flattened base) shaped and intermediate defining component establishes dual and spaced apart universal and rotating and/or articulating surfaces with the spatially mounted first and second receivers, thereby providing evenly distributed wear profiles for increased useful life of the implant, as well as relieving associated ligament tension.

2. Description of the Background Art

The prior art discloses various types of artificial implants, such as replacing damaged natural joint constructions including those for the shoulder. Examples of these include each of the modular humeral head resurfacing system of Winslow et al., US 2006/0009852 and US 2005/0107882, each of which incorporates a two piece humeral component for use in joint arthroplasty which is adapted to be implanted into a joint and engaged by a likewise implanted socket component.

SUMMARY OF THE PRESENT INVENTION

The present invention discloses an implant assembly for re-establishing a glenohumeral joint between a scapula and humerus. A first receiver is adapted to being mounted to a reconditioned glenoid cavity defined in the scapula, with a second receiver adapted to being mounted to a reconditioned humeral head associated with the humerus. A three dimensional and at least partially spherical shaped element is interposed between the first and second receivers for establishing at least one of articulating and rotating support at respective and spaced apart seating profiles.

Additional features include the first receiver exhibiting a first concave profile seating a first spherical shaped portion of the interposed three dimensional component for establishing a first universal articulating support. A bulbous projection extends from a planar annular profile associated with the second receiver for resistively fitting within a generally opposite facing and mating undercut profile defined a flattened profile defined in the three dimensional component amd for providing, in combination with the first articulating support, a second rotational support.

The first receiver exhibits a first concave recess defined in an exposed face for seating in articulating fashion a first portion of an interposed spherical component. The second receiver exhibits a second concave recess defined in an exposed face for seating in like articulating fashion a second portion of the spherical element.

The first receiver has an enlarged concave profile with a tapered extending rim for establishing enhanced shouldering support of an increased seating portion of the spherical component. Each of the first and second receiver components and interposed spherical component may also be constructed of an alternating material including at least one of a polymer, polymer composite, metal, metal composite or polymer/metal admixture.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1 is an assembled view of a first shoulder implant assembly;

FIG. 2 is an exploded view of the multi-component implant arrangement of FIG. 1 for reconditioned re-engagement of a patient's scapula and upper humerus bones and better depicting the respective mounted first and second uniquely configured receiver components, along with an intermediate and universally inter-supported and substantially spherical shaped component exhibiting a flattened profile opposing the humeral head mounted receiver with projecting bulb seating portion and in order to provide rotating support in combination with universal articulating support separately established between the intermediate component and the opposite scapula bone mounted receiver;

FIG. 3 is an assembled view of a modified shoulder implant assembly;

FIG. 4 is an exploded view of the multi-component arrangement of FIG. 3, similar to the previous depiction of FIG. 2, and better illustrating the modified nature of shoulder implant assembly in which a modified/enlarged and tapered concavity profile is formed in the scapula bone mounted receiver component, combined with a redesign of the second humeral head mounted receiver, and with the inter-supported element exhibiting a complete spherical shape;

FIG. 5 is an assembled view of a yet further modified shoulder implant assembly; and

FIG. 6 is an exploded view of the arrangement of FIG. 5 and better depicting the arrangement of a scapula mounted first receiver such as depicted in FIGS. 1-2, combined with a second receiver configured as shown in FIGS. 3-4, and in combination with a fully spherical shaped intermediate component for providing universal articulating support along each of two individual locations established between the humerus mounting receiver and intermediate component, and separately an opposite end profile of the intermediate component and the other receiver mounted in the scapula; and

FIGS. 7-9 depict a series of supporting Prior Art illustrations of a human anatomical shoulder joint, and for which the multi-component assembly provides an in situ and reconditioned implantation option.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As will be described in additional detail with reference to the succeeding variants, the present invention discloses a multi-component shoulder implant assembly for providing an in-situ and reconditioned installation option which is an improvement over other conventional joint implant installations.

Prior to describing in detail the configurations of the various embodiments of multi-component shoulder implants, respectively depicted in FIGS. 1-2, 3-4 and 5-6, a Prior Art depiction of an anatomically correct human shoulder is shown in FIGS. 7-9 and which includes three bones consisting of the clavicle (collarbone) 1, the scapula (shoulder blade) 2, and the humerus (upper arm bone) 3, as well as associated muscles, ligaments and tendons (see in particular FIGS. 8 and 9). The articulations between the bones of the shoulder collectively make up the shoulder joints where the humerus 3 attaches to the scapula 2.

An abbreviated and incomplete description of the scapula further includes, at strategic locations a coracoid process 4 and spine connected acromion 5, in the proximity of which is configured the glenoid cavity 6. The humerus 3 terminates, in relevant part, at an upper end located humeral head 7 (FIG. 8) which generally seats via an interposed bursa 8 (FIG. 7).

The three joints of the shoulder further include each of the glenohumeral, acromioclavicular and sternoclavicular joints. The glenohumeral joint, see as identified at 9 in FIG. 9, is the main joint of the shoulder and the generic term “shoulder joint” usually refers to this ball and socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body.

As is best depicted in the prior art view of FIG. 8, associated types of joint cartilage include articular cartilage located on the ends of the bones and which allows the bones to glide and move on each other and labrum cartilage located in the shoulder. In combination, the shoulder as constructed exhibits sufficient mobile for undertaking a wide range of actions of the arms and hands as well as being sufficiently stable as to allow for actions such as lifting, pushing and pulling. This compromise between mobility and stability results in a large number of shoulder problems not faced by other joints such as the hip.

With reference now to the embodiments of the invention set forth in FIGS. 1-6, and for purposes of ease and clarity of illustration, a simplified depiction is shown of the glenohumeral joint established between the scapula 2 and humerus 3 and in which all ligaments, muscles and tendons are removed. In each instance, and prior to installation of the multi-component implant assembly (such as occurring after significant degradation of the natural glenohumeral joint or in other instances in which an accident or other traumatic incident has resulted in significant damage), an initial (in situ) surgical reconditioning procedure is employed of the opposing joint defining surfaces established by the humeral head 7 and the glenoid cavity 6. This includes employing relevant surgical drilling and shaping instruments (also not shown) in order to prepare the joint defining locations of the bones for subsequently attaching selected components associated with the implant assembly and as will now be described.

The above stated, and referring initially to each of FIGS. 1 and 2, a pair of assembled and exploded views, both generally at 10, are depicted of a first variant of shoulder implant assembly for installation within reconditioned and opposing end locations of the patient's scapula 2 (represented by reconditioned profile 12) and humerus (further represented by reconditioned profile 14), and as is best shown in the exploded view of FIG. 2. The implant assembly 10 includes, collectively, a first receiver shaped component 16 which is mounted within the reconditioned recess 12 of the scapula glenoid cavity.

A secondary and pseudo-receiver shaped component 18 likewise mounted within the reconditioned recess 14 of the upper humeral head. The secondary receiver 18 exhibits a planar and generally annular shaped surface profile 20 from which generally centrally projects a bulbous portion 22 which is interconnected to the planar surface profile 20 via a narrowed neck.

Each of the first receiver 16 and second receiver 18 further includes a uniquely configured stem portion, see at 24 and 26, respectively, which seats within hidden configured recess configurations (not shown) established within the reconditioned innermost profile 12 of the scapula glenoid cavity and within the corresponding humeral head reconditioned profile 14. In a typical surgical procedure, a medical bonding cement or other suitable fastener/adhesive (not shown) is employed for anchoring the receivers 16 and 18 to the respective bone locations 2 and 3, it being further understood that the configuration of these elements is capable of being reversed (e.g. so that the receiver 16 is mounted to the humeral head and the receiver 18 reversed to mount to the scapula glenoid cavity).

An intermediate and universally inter-supported and substantially (also termed pseudo or partial) spherical shaped component is depicted at 26 exhibiting a flattened profile 28 opposing the humeral head mounted receiver 18 with projecting bulb seating portion 22, the flattened profile 28 and bulbous portion 22 exhibited in a generally opposite facing direction relative to a spherical profile of the component 26 seating with the first receiver 16. Although not clearly shown in FIG. 2, a corresponding and bulbous enlarged undercut profile is formed in a hidden recess location of the flattened end profile 28 of the pseudo-spherical shaped component 26 of FIG. 2, and into which is resistively installed (such as through a press-fit installation), the bulbous seating portion 22 in order to provide rotating support (see arrow 30) between the humeral head receiver 18 and the flattened support profile 28 of the intermediate three dimensional component 26. Separately, a further recess concave profile, largely hidden from view but generally designated at 32 in FIG. 2, is formed in the outward facing perimeter of the scapula mounted first receiver 16 and, in combination with rotating support separately established between the pseudo-spherical intermediate component and the opposite scapula bone mounted receiver, establishes first rotating and second spaced and articulating surfaces within the joint assembly.

The first receiver 16, second 18 and inter-disposed pseudo-spherical element 26 are each constructed of any suitable material including any type of plastic, metal or admixed composite. While not limited to any specific variant, the material selection for these components can alternate between the components, such as for example the first scapula mounted receiver 16 and second humeral head mounted receiver 18 being constructed of a first material (e.g. heavy duty, wear resistant and sanitary polymeric, polymeric composite, surgical steel/aluminum, other metal or metal composite, as well as plastic/metal admixture), and with the inter-disposed pseudo-spherical element 26 being constructed of a secondary/alternating material selected from such as the other of the identified materials.

Although not shown, the existing arrangement of ligaments, tendons and muscles provide the anchoring/seating support for retaining the articulating relationships established between the first and second uniquely configured receiver shaped elements 16 and 18 and interposed pseudo-spherical element 26, it further being understood that these components are capable of being retrofit installed within the reconditioned bone ends of the patient without the necessity of the ligaments and tendons being severed of otherwise impacted, thereby enhancing the universal motion profile afforded by the design and likewise reducing recovery time for the patient. As previously described, the ability to segment a combination of rotational and universal/articulating motion of the glenohumeral joint into a pair of spaced apart profiles serves to both enhance artificial joint mobility as well as to more evenly distribute an associated wear profile of the joint, thereby increasing expected life of the assembly.

Referring now to FIGS. 3 and 4, FIG. 4 a pair of assembled and exploded views are shown of a modified shoulder implant assembly, generally at 34, in which a modified/enlarged and tapered concavity profile is formed in the scapula bone mounted receiver component, combined with a redesign of the second humeral head mounted receiver, and with the inter-supported element exhibiting a complete spherical shape. Specifically, redesigned first receiver 36 exhibits an enlarged configuration in comparison to that depicted at 16 in FIGS. 1-2, with similar configured stem mounting portion 38. Enlarged concavity profile 40 is further exhibited and round which extends a tapered perimeter rim 42, such that an intermediate spherical element 44 is seated within the concave profile in the fashion as further depicted in FIG. 3.

A correspondingly redesigned second humeral head mounted receiver 46 exhibits an extending and anchoring stem portion 48 (again generally matching the inner machine profile associated with the humeral head recess 14). A further concave profile 50 is formed in an outwardly facing direction of the second receiver 46 and which is bound by a generally level and planar outer rim 52.

Upon installation, the flared profile 42 of the first scapula mounted receiver 36 provides enhanced universal articulating and shouldering support with one seating side of the spherical intermediate element 44, combined with the additional level of universal articulating and seating support established by the seating profile established by the second receiver element 46. As best shown in FIG. 3, the assembled arrangement is such that the outer tapered profile 42 of the first receiver 36 approaches the outer perimeter rim 52 of the second receiver 46 depending upon the angular orientation established between the humerus bone relative to the scapula, with the overall dimensioning of the seating/support surfaces being such that an optimization of seating support and articulating range of motion is maximized.

With reference finally to FIGS. 5 and 6, successive assembled and exploded views are respectively shown depicting the arrangement of a scapula mounted first receiver 16, such as depicted in FIGS. 1-2, combined with a second receiver 46 configured as shown in FIGS. 3-4, and in combination again with a fully spherical shaped intermediate component 44 for providing universal articulating support along each of two individual locations established between the humerus mounting receiver 46 and intermediate component 44, and separately an opposite end profile of the intermediate component 44 and the other receiver 16 mounted in the scapula 2. In this fashion, the assembled joint assembly depicted in FIG. 5, differs marginally from that shown in FIG. 3 owing to the less significant degree of shouldering/seating support by the first receiver 16 (in comparison to the enhanced support depicted by the modified receiver 36 of FIG. 4 and which illustrates the tradeoff established between range of motion and support evidenced by these varying implant arrangements) depicted versus that associated with the second humeral head mounted receiver component 46.

Having now described our invention, other and additional preferred embodiments will become evident to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims. 

1. An implant assembly for re-establishing a glenohumeral joint between a scapula and humerus, comprising: a first receiver adapted to being mounted to a reconditioned glenoid cavity defined in the scapula; a second receiver adapted to being mounted to a reconditioned humeral head associated with the humerus; and a three dimensional and at least partially spherical shaped element interposed between said first and second receivers for establishing at least one of articulating and rotating support at respective and spaced apart seating profiles.
 2. The assembly as described in claim 1, further comprising said first receiver exhibiting a first concave profile seating a first spherical shaped portion of said interposed three dimensional component for establishing a first universal articulating support, a bulbous projection extending from a planar annular profile associated with said second receiver resistively fitting within a generally opposite facing and mating undercut profile defined a flattened profile defined in said three dimensional component for providing, in combination with said first articulating support, a second rotational support.
 3. The assembly as described in claim 1, further comprising said first receiver exhibiting a first concave recess defined in an exposed face for seating in articulating fashion a first portion of an interposed spherical component, said second receiver exhibiting a second concave recess defined in an exposed face for seating in like articulating fashion a second portion of said spherical element.
 4. The assembly as described in claim 3, said first receiver further comprising an enlarged concave profile with a tapered extending rim for establishing enhanced shouldering support of an increased seating portion of said spherical component.
 5. The assembly as described in claim 2, each of said first and second receiver components and interposed spherical component being constructed of an alternating material including at least one of a polymer, polymer composite, metal, metal composite or polymer/metal admixture.
 6. An implant assembly for re-establishing a glenohumeral joint between a scapula and humerus, comprising: a first receiver adapted to being mounted to a reconditioned glenoid cavity defined in the scapula; a second receiver adapted to being mounted to a reconditioned humeral head associated with the humerus; a three dimensional and at least partially spherical shaped element interposed between said first and second receivers for establishing at least one of articulating and rotating support at respective and spaced apart seating profiles; and said first receiver exhibiting a first concave profile seating a first spherical shaped portion of said interposed three dimensional component for establishing a first universal articulating support, a bulbous projection extending from a planar annular profile associated with said second receiver resistively fitting within a generally opposite facing and mating undercut profile defined a flattened profile defined in said three dimensional component for providing, in combination with said first articulating support, a second rotational support.
 7. The assembly as described in claim 6, each of said first and second receiver components and interposed spherical component being constructed of an alternating material including at least one of a polymer, polymer composite, metal, metal composite or polymer/metal admixture.
 8. An implant assembly for re-establishing a glenohumeral joint between a scapula and humerus, comprising: a first receiver adapted to being mounted to a reconditioned glenoid cavity defined in the scapula; a second receiver adapted to being mounted to a reconditioned humeral head associated with the humerus; a three dimensional and at least partially spherical shaped element interposed between said first and second receivers for establishing at least one of articulating and rotating support at respective and spaced apart seating profiles; and said first receiver exhibiting a first concave recess defined in an exposed face for seating in articulating fashion a first portion of an interposed spherical component, said second receiver exhibiting a second concave recess defined in an exposed face for seating in like articulating fashion a second portion of said spherical element.
 9. The assembly as described in claim 8, said first receiver further comprising an enlarged concave profile with a tapered extending rim for establishing enhanced shouldering support of an increased seating portion of said spherical component.
 10. The assembly as described in claim 8, each of said first and second receiver components and interposed spherical component being constructed of an alternating material including at least one of a polymer, polymer composite, metal, metal composite or polymer/metal admixture. 